Preparation and application of chlorine dioxide, and security considerations about it in transport and use were introduced. New preparation method of solid ClO2 was proposed. That is : with sodium chlorite as main raw material, in the presence of solid sodium bisulfate and sodium bicarbonate as effervescent agent, salt as binder, sodium dichloroisocyanurate as additive, magnesium sulfate as stabilizer, vinyl pyrrolidone, film former, as carrier, reactive ClO2 was formed，meanwhile the transport and use security of solid ClO2 must be considered.